Benzoimidazol-2-yl pyrimidine modulators of the histamine H4 receptor

ABSTRACT

Benzoimidazol-2-yl pyrimidines, purification methods for the same, and pharmaceutical compositions and methods for the treatment of disease states, disorders, and conditions mediated by H 4  receptor activity, including allergy, asthma, autoimmune diseases, and pruritus.

This application is a divisional application of U.S. Ser. No.14/465,677, filed on Aug. 21, 2015, which is a continuation applicationof U.S. Ser. No. 14/199,634, filed Mar. 6, 2014 (now U.S. Pat. No.8,859,575), which two applications are incorporated herein by reference,and said application Ser. No. 14/199,634 claims the benefit of U.S.Provisional Application 61/773,706, filed on Mar. 6, 2013, U.S.Provisional Application 61/776,260, filed on Mar. 11, 2013, and U.S.Provisional Application 61/784,909, filed on Mar. 14, 2013.

FIELD OF THE INVENTION

The present invention relates to certain benzoimidazol-2-yl pyrimidines,purification methods for the same, pharmaceutical compositionscontaining them, methods of obtaining and using them for the treatmentof disease states, disorders, and conditions mediated by histamine H₄receptor activity.

BACKGROUND OF THE INVENTION

The histamine H₄ receptor (H₄R) is one of the identified receptors forhistamine (for reviews, see: Fung-Leung, W.-P., et al., Curr. Opin.Invest. Drugs 2004, 5(11), 1174-1183; de Esch, I. J. P., et al., TrendsPharmacol. Sci. 2005, 26(9), 462-469). The receptor is found in the bonemarrow and spleen and is expressed on eosinophils, basophils, mast cells(Liu, C., et al., Mol. Pharmacol. 2001, 59(3), 420-426; Morse, K. L., etal., J. Pharmacol. Exp. Ther. 2001, 296(3), 1058-1066; Hofstra, C. L.,et al., J. Pharmacol. Exp. Ther. 2003, 305(3), 1212-1221; Lippert, U.,et al., J. Invest. Dermatol. 2004, 123(1), 116-123; Voehringer, D., etal., Immunity 2004, 20(3), 267-277), CD8⁺ T cells (Gantner, F., et al.,J. Pharmacol. Exp. Ther. 2002, 303(1), 300-307), dendritic cells, andhuman synovial cells from rheumatoid arthritis patients (Ikawa, Y., etal., Biol. Pharm. Bull. 2005, 28(10), 2016-2018). However, expression inneutrophils and monocytes is less well defined (Ling, P., et al., Br. J.Pharmacol. 2004, 142(1), 161-171). Receptor expression is at least inpart controlled by various inflammatory stimuli (Coge, F., et al.,Biochem. Biophys. Res. Commun. 2001, 284(2), 301-309; Morse, et al.,2001), thus supporting that H₄ receptor activation influencesinflammatory responses. Because of its preferential expression onimmunocompetent cells, the H₄ receptor is closely related with theregulatory functions of histamine during the immune response.

A biological activity of histamine in the context of immunology andautoimmune diseases is closely related with the allergic response andits deleterious effects, such as inflammation. Events that elicit theinflammatory response include physical stimulation (including trauma),chemical stimulation, infection, and invasion by a foreign body. Theinflammatory response is characterized by pain, increased temperature,redness, swelling, reduced function, or a combination of these.

Mast cell degranulation (exocytosis) releases histamine and leads to aninflammatory response that may be initially characterized by ahistamine-modulated wheal and flare reaction. A wide variety ofimmunological stimuli (e.g., allergens or antibodies) andnon-immunological (e.g., chemical) stimuli may cause the activation,recruitment, and de-granulation of mast cells. Mast cell activationinitiates allergic inflammatory responses, which in turn cause therecruitment of other effector cells that further contribute to theinflammatory response. It has been shown that histamine induceschemotaxis of mouse mast cells (Hofstra, et al., 2003). Chemotaxis doesnot occur using mast cells derived from H₄ receptor knockout mice.Furthermore, the response is blocked by an H₄-specific antagonist, butnot by H₁, H₂ or H₃ receptor antagonists (Hofstra, et al., 2003;Thurmond, R. L., et al., J. Pharmacol. Exp. Ther. 2004, 309(1),404-413). The in vivo migration of mast cells to histamine has also beeninvestigated and shown to be H₄ receptor dependent (Thurmond, et al.,2004). The migration of mast cells may play a role in allergic rhinitisand allergy where increases in mast cell number are found (Kirby, J. G.,et al., Am. Rev. Respir. Dis. 1987, 136(2), 379-383; Crimi, E., et al.,Am. Rev. Respir. Dis. 1991, 144(6), 1282-1286; Amin, K., et al., Am. J.Resp. Crit. Care Med. 2000, 162(6), 2295-2301; Gauvreau, G. M., et al.,Am. J. Resp. Crit. Care Med. 2000, 161(5), 1473-1478; Kassel, O., etal., Clin. Exp. Allergy 2001, 31(9), 1432-1440). In addition, it isknown that in response to allergens there is a redistribution of mastcells to the epithelial lining of the nasal mucosa (Fokkens, W. J., etal., Clin. Exp. Allergy 1992, 22(7), 701-710; Slater, A., et al., J.Laryngol. Otol. 1996, 110, 929-933). These results show that thechemotactic response of mast cells is mediated by histamine H₄receptors.

It has been shown that eosinophils can chemotax towards histamine(O'Reilly, M., et al., J. Recept. Signal Transduction 2002, 22(1-4),431-448; Buckland, K. F., et al., Br. J. Pharmacol. 2003, 140(6),1117-1127; Ling et al., 2004). Using H₄ selective ligands, it has beenshown that histamine-induced chemotaxis of eosinophils is mediatedthrough the H₄ receptor (Buckland, et al., 2003; Ling et al., 2004).Cell surface expression of adhesion molecules CD11b/CD18 (LFA-1) andCD54 (ICAM-1) on eosinophils increases after histamine treatment (Ling,et al., 2004). This increase is blocked by H₄ receptor antagonists butnot by H₁, H₂, or H₃ receptor antagonists.

The H₄R also plays a role in dendritic cells and T cells. In humanmonocyte-derived dendritic cells, H₄R stimulation suppresses IL-12p70production and drives histamine-mediated chemotaxis (Gutzmer, R., etal., J. Immunol. 2005, 174(9), 5224-5232). A role for the H₄ receptor inCD8⁺ T cells has also been reported. Gantner, et al., (2002) showed thatboth H₄ and H₂ receptors control histamine-induced IL-16 release fromhuman CD8+ T cells. IL-16 is found in the bronchoalveolar fluid ofallergen- or histamine-challenged asthmatics (Mashikian, V. M., et al.,J. Allergy Clin. Immunol. 1998, 101 (6, Part 1), 786-792; Krug, N., etal., Am. J. Resp. Crit. Care Med. 2000, 162(1), 105-111) and isconsidered important in CD4⁺ cell migration. The activity of thereceptor in these cell types indicates an important role in adaptiveimmune responses such as those active in autoimmune diseases.

In vivo H₄ receptor antagonists were able to block neutrophillia inzymosan-induced peritonitis or pleurisy models (Takeshita, K., et al.,J. Pharmacol. Exp. Ther. 2003, 307(3), 1072-1078; Thurmond, R., et al.,2004). In addition, H₄ receptor antagonists have activity in a widelyused and well-characterized model of colitis (Varga, C., et al., Eur. J.Pharmacol. 2005, 522(1-3), 130-138). These results support theconclusion that H₄ receptor antagonists have the capacity to beanti-inflammatory in vivo.

Another physiological role of histamine is as a mediator of itch and H₁receptor antagonists are not completely effective in the clinic.Recently, the H₄ receptor has also been implicated in histamine-inducedscratching in mice (Bell, J. K., et al., Br. J. Pharmacol. 2004, 142(2),374-380). The effects of histamine could be blocked by H₄ antagonists.These results support the hypothesis that the H₄ receptor is involved inhistamine-induced itch and that H₄ receptor antagonists will thereforehave positive effects in treating pruritus.

Modulation of H₄ receptors controls the release of inflammatorymediators and inhibits leukocyte recruitment, thus providing the abilityto prevent and/or treat H₄-mediated diseases and conditions, includingthe deleterious effects of allergic responses such as inflammation.Compounds according to the present invention have H₄ receptor modulatingproperties. Compounds according to the present invention have leukocyterecruitment inhibiting properties. Compounds according to the presentinvention have anti-inflammatory properties.

Examples of textbooks on the subject of inflammation include: Gallin, J.I.; Snyderman, R., Inflammation: Basic Principles and ClinicalCorrelates, 3rd ed.; Lippincott Williams & Wilkins: Philadelphia, 1999;Stvrtinova, V., et al., Inflammation and Fever. PathophysiologyPrinciples of Diseases (Textbook for Medical Students); Academic Press:New York, 1995; Cecil; et al. Textbook Of Medicine, 18th ed.; W.B.Saunders Co., 1988; and Stedman's Medical Dictionary.

Background and review material on inflammation and conditions relatedwith inflammation can be found in articles such as the following:Nathan, C., Nature 2002, 420(6917), 846-852; Tracey, K. J., Nature 2002,420(6917), 853-859; Coussens, L. M., et al., Nature 2002, 420(6917),860-867; Libby, P., Nature 2002, 420, 868-874; Benoist, C., et al.,Nature 2002, 420(6917), 875-878; Weiner, H. L., et al., Nature 2002,420(6917), 879-884; Cohen, J., Nature 2002, 420(6917), 885-891;Steinberg, D., Nature Med. 2002, 8(11), 1211-1217.

Thus, small-molecule histamine H₄ receptor modulators according to thisinvention control the release of inflammatory mediators and inhibitleukocyte recruitment, and may be useful in treating inflammation ofvarious etiologies, including the following conditions and diseases:inflammatory disorders, allergic disorders, dermatological disorders,autoimmune disease, lymphatic disorders, pruritus, and immunodeficiencydisorders. Diseases, disorders and medical conditions that are mediatedby histamine H₄ receptor activity include those referred to herein.

Histamine H₄ receptor modulators have been described in, for example:U.S. Pat. No. 7,432,378; U.S. Pat. No. 7,507,737; U.S. Pat. No.8,343,989; U.S. Pat. Appl. Publ. 2009/0137608; U.S. patent applicationSer. No. 13/676,595 (U.S. Pat. No. 8,598,189); U.S. Pat. No. 8,309,720;U.S. patent application Ser. No. 13/663,233; and U.S. Pat. Appl. Publ.2011/0076324, all of which are incorporated by reference herein.Histamine H₄ receptor modulators have also been described in, forexample, U.S. Pat. Appl. Publ. 2010/0029942; U.S. Pat. Appl. Publ.2012/0184740; U.S. Pat. Appl. Publ. 2012/0178932, and WO2010/002777.However, there still remains a need for histamine H₄ receptor modulatorswith desirable pharmaceutical properties.

As to specific forms of such modulators, active pharmaceuticalingredients that are initially in free base form are often convertedinto their salt forms to improve certain of their pharmaceuticalproperties. There is typically a plurality of salts that can be madefrom a sufficiently basic compound, as is the case with compoundsdescribed in this application. As to specific salts, a specific solvateof the same, if any, and of such, the specific degree of solvation thatwill lead to a certain desired improvement of pharmaceutical properties,are often unpredictable. This has been recognized in, for example,WO2012/060590, which states, inter alia, that “there is no generaltendency, for example, to prefer the hydrate to the anhydrate or viceversa, for the improvement of pharmaceutical properties including drugstability, hygroscopic property, etc.”, and that optimization ofpharmaceutical properties is to be made on a case-by-case basis.Physical pharmaceutical properties, such as hygroscopicity,crystallinity, melting point, solubility, dissolution rate, and impuritysegregation ability, can present predictability challenges. Furthermore,identifying a specific form of an active pharmaceutical compound thatoptimally presents such properties for desirable formulations of thesame compound can be in certain instances difficult to accomplish.Because of these limitations in what one of ordinary skill in the artwould be able to expect regarding such properties, and the role thatthey play in certain aspects of the pharmaceutical industry, there stillremains a need for finding specific forms of certain pharmaceuticalcompounds with improved properties, such as those illustratively listedabove.

SUMMARY OF THE INVENTION

This invention relates to a hydrated hemitartrate benzoimidazol-2-ylpyrimidine as shown by the following structural formula and methods ofusing, obtaining and purifying the same.

This invention also relates to a fumarate and a phosphate of the samebenzoimidazol-2-yl pyrimidine.

In a further aspect, the invention relates to pharmaceuticalcompositions each comprising an effective amount of at least one of theabove compounds.

In another aspect, the invention is directed to a method of treating asubject suffering from or diagnosed with a disease, disorder, or medicalcondition mediated by histamine H₄ receptor activity, comprisingadministering to the subject in need of such treatment an effectiveamount of at least one of the above compounds or a pharmaceuticallyacceptable salt thereof, pharmaceutically acceptable prodrug, orpharmaceutically active metabolite of such compounds. In certainpreferred embodiments of the inventive method, the disease, disorder, ormedical condition is inflammation. Inflammation herein refers to theresponse that develops as a consequence of histamine release, which inturn is caused by at least one stimulus. Examples of such stimuli areimmunological stimuli and non-immunological stimuli.

In another aspect, the invention is directed to a method for modulatinghistamine H₄ receptor activity, comprising exposing a histamine H₄receptor to an effective amount of at least one of the above compounds.

In another aspect the invention is directed to the making, includingpurifying the above compounds.

Additional embodiments, features, and advantages of the invention willbe apparent from the following detailed description and through practiceof the invention.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1. Powder X-ray diffraction (XRD) profile of Compound 2.2

FIG. 2. Comparison of impurity segregation profiles for Compounds 2 and3 (See also Example 5)

FIG. 3. Comparison of impurity segregation profiles for Compounds 2.1and 3 (See also Example 7)

FIG. 4. XRD profile of Compound 3

FIG. 5. Comparison of impurity segregation profiles for Compounds 2 and4 (See also Example 9)

FIG. 6. Differential Scanning calorimetry (DSC) and ThermogravimetricAnalysis (TGA) of Compound 2.1

FIG. 7. DSC and TGA of Compound 3

FIG. 8. DSC and TGA of Compound 2.2

FIG. 9. XRD profiles of Compounds 2.1, 2.2 and 3

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the terms “including”, “containing” and “comprising” areused in their open, non-limiting sense.

Unless qualified specifically in particular instances of use, the term“low alkyl” or “low-alkyl” refers to a straight- or branched-chain alkylgroup having from 1 to 6 carbon atoms in the chain. Examples of alkylgroups include methyl (Me), ethyl (Et), n-propyl, isopropyl, butyl,isobutyl, sec-butyl, tert-butyl (tBu), pentyl, isopentyl, tert-pentyl,hexyl, isohexyl, and groups that in light of the ordinary skill in theart and the teachings provided herein would be considered equivalent toany one of the foregoing examples. “C₁₋₄alkyl” refers to straight- orbranched-chain alkyl group having from 1 to 4 carbon atoms in the chain.

Any formula given herein is also intended to represent unlabeled formsas well as isotopically labeled forms of the compounds. Isotopicallylabeled compounds have structures depicted by the formulas given hereinexcept that one or more atoms are replaced by an atom having a selectedatomic mass or mass number. Examples of isotopes that can beincorporated into compounds of the invention include isotopes ofhydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine, chlorine, andiodine, such as ²H, ³H, ¹¹C, ¹³C, ¹⁴C, ¹⁵N, ¹⁸O, ¹⁷O, ³¹P, ³²P, ³⁵S,¹⁸F, ³⁶Cl, and ¹²⁵I respectively. Such isotopically labelled compoundsare useful in metabolic studies (preferably with ¹⁴C), reaction kineticstudies (with, for example ²H or ³H), detection or imaging techniques[such as positron emission tomography (PET) or single-photon emissioncomputed tomography (SPECT)] including drug or substrate tissuedistribution assays, or in radioactive treatment of patients. Inparticular, an ¹⁸F or ¹¹C labeled compound may be particularly preferredfor PET or SPECT studies. Further, substitution with heavier isotopessuch as deuterium (i.e., ²H) may afford certain therapeutic advantagesresulting from greater metabolic stability, for example increased invivo half-life or reduced dosage requirements. Isotopically labeledcompounds of this invention and prodrugs thereof can generally beprepared by carrying out the procedures disclosed in the schemes or inthe examples and preparations described below by substituting a readilyavailable isotopically labeled reagent for a non-isotopically labeledreagent.

When referring to any formula given herein, the selection of aparticular moiety from a list of possible species for a specifiedvariable is not intended to define the same choice of the species forthe variable appearing elsewhere. In other words, where a variableappears more than once in the same formula, the choice of the speciesfrom a specified list is independent of the choice of the species forthe same variable elsewhere in the formula, unless stated otherwise.

Compound 2 has H₄ receptor modulator activity as described in, forexample U.S. Pat. No. 7,507,737, U.S. Pat. No. 8,343,989, U.S.Application Publ. US2009/0137608 and U.S. application Ser. No.13/676,595 (U.S. Pat. No. 8,598,189), all of which are incorporatedherein by reference:

It has been found in the context of this invention that the hemitartratetetrahydrate of Compound 2, referred to herein as Compound 3, hasimproved desirable physical pharmaceutical properties, which make of itan even more suitable chemical entity for the prevention or treatment ofmedical conditions, diseases or disorders mediated by H₄ receptoractivity. Impurities in pharmaceuticals are unwanted chemicals thatremain with the active pharmaceutical ingredients after their synthesis,develop during formulation, or when active pharmaceutical ingredients,whether formulated as medicines or not, are aged to medicines. Thecontrol of pharmaceutical impurities is an important issue to thepharmaceutical industry. It has been discovered that Compound 3 hasimpurity segregation properties that confer to it improved physicalpharmaceutical properties because its synthesis permits the moreefficient removal of impurities and/or the removal of impurities to anextent such that otherwise would require more laborious purificationprocesses.

Compound 3 can be administered to treat inflammation. Inflammation maybe associated with various diseases, disorders, or conditions, such asinflammatory disorders, allergic disorders, dermatological disorders,autoimmune disease, lymphatic disorders, and immunodeficiency disorders,including the more specific conditions and diseases given below.Regarding the onset and evolution of inflammation, inflammatory diseasesor inflammation-mediated diseases or conditions include, but are notlimited to, acute inflammation, allergic inflammation, and chronicinflammation.

Illustrative types of inflammation treatable with a histamine H₄receptor-modulating agent according to the invention includeinflammation due to or associated with any one of a plurality ofconditions such as allergy, asthma, eosinophilic asthma, dry eye,chronic obstructive pulmonary disease (COPD), atherosclerosis,rheumatoid arthritis, multiple sclerosis, inflammatory bowel diseases(including colitis, Crohn's disease, and ulcerative colitis), psoriasis,pruritus, itchy skin, atopic dermatitis, urticaria (also known ashives), ocular inflammation, conjunctivitis, nasal polyps, allergicrhinitis, nasal itch, parasitic or fungal infections (e.g., lice,scabies, swimmer's itch, jock itch, athlete's foot), hidradenitissuppurativa, malignancy, such as lymphoma (e.g., Hodgkin's disease),jaundice, polycythemia, punctate palmoplantar keratoderma, thyroidillness/hyperparathyroidism, diabetes, chicken pox, iron deficiencyanemia, psychiatric diseases, medication-induced itch (e.g., allergies,photodermatitis, morphine, opiates, chloroquine); cholestasis;pregnancy-related itch (e.g., obstetric cholestasis, pruritic urticariapapules and plaques of pregnancy, gestational pemphigoid); xerosis (alsoknown as dry skin), sunburn, dandruff, scab/scars, insect bites, poisonivy/oak, hemorrhoids, contact dermatitis, old-age associated itch, itchassociated with dialysis, scleroderma, autoimmune thyroid diseases,immune-mediated (also known as type 1) diabetes mellitus and lupus,which are characterized by excessive or prolonged inflammation at somestage of the disease. Other autoimmune diseases that lead toinflammation include Myasthenia gravis, autoimmune neuropathies, such asGuillain-Barré, autoimmune uveitis, autoimmune hemolytic anemia,pernicious anemia, autoimmune thrombocytopenia, temporal arteritis,anti-phospholipid syndrome, vasculitides, such as Wegener'sgranulomatosis, Behcet's disease, dermatitis herpetiform is, pemphigusvulgaris, vitiligio, primary biliary cirrhosis, autoimmune hepatitis,autoimmune oophoritis and orchitis, autoimmune disease of the adrenalgland, polymyositis, dermatomyositis, spondyloarthropathies, such asankylosing spondylitis, Sjogren's syndrome and pruritus.

Pruritus includes that which is a symptom of allergic cutaneous diseases(such as atopic dermatitis and hives) and other metabolic disorders(such as chronic renal failure, hepatic cholestasis, and diabetesmellitus).

Compound 3 can also be administered to treat mood disorders (includingbut not limited to major depressive disorder, bipolar disorder,treatment resistant major depressive disorder and treatment resistantbipolar disorder), anxiety disorders (including but not limited togeneralized anxiety disorder, social phobia, and post traumatic stressdisorder).

Compound 3 may also be administered with a long acting β-agonist, actingin a synergistic manner to improve lung functions and asthma in thetreatment of asthma.

In another embodiment, Compound 3 is administered to treat allergy,asthma, autoimmune diseases, or pruritus.

The term “treat” or “treating” as used herein is intended to refer toadministration of Compound 3 to a subject for the purpose of effecting atherapeutic or prophylactic benefit through modulation of histamine H₄receptor activity. Treating includes reversing, ameliorating,alleviating, inhibiting the progress of, lessening the severity of, orpreventing a disease, disorder, or condition, or one or more symptoms ofsuch disease, disorder or condition mediated through modulation ofhistamine H₄ receptor activity. The term “subject” refers to a mammalianpatient in need of such treatment, such as a human. “Modulators” includeboth inhibitors and activators, where “inhibitors” refer to compoundsthat decrease, prevent, inactivate, desensitize or down-regulatehistamine H₄ receptor expression or activity, and “activators” arecompounds that increase, activate, facilitate, sensitize, or up-regulatehistamine H₄ receptor expression or activity.

In treatment methods according to the invention, an effective amount ofat least Compound 3 is administered to a subject suffering from ordiagnosed as having such a disease, disorder, or condition. An“effective amount” means an amount or dose sufficient to generally bringabout the desired therapeutic or prophylactic benefit in patients inneed of such treatment for the designated disease, disorder, orcondition. Effective amounts or doses of Compound 3 may be ascertainedby routine methods such as modeling, dose escalation studies or clinicaltrials, and by taking into consideration routine factors, e.g., the modeor route of administration or drug delivery, the pharmacokinetics of theagent, the severity and course of the disease, disorder, or condition,the subject's previous or ongoing therapy, the subject's health statusand response to drugs, and the judgment of the treating physician. Anexample of a dose is in the range of from about 0.001 to about 200 mg offree base equivalent per kg of subject's body weight per day, preferablyabout 0.01 to 7 mg/kg/day, most preferably about 0.04 to 1.4 mg/kg/day,in single or divided dosage units (e.g., twice a day, three times a day,four times a day). For a 70-kg human, an illustrative range for asuitable oral dosage amount of free base equivalent is from about 0.05to about 300 mg/day, or preferably about 1 to 50 mg/day, more preferablyfrom about 3 to 30 mg/day, most preferably a dose of 3 mg/day or 10mg/day or 30 mg/day.

Once improvement of the patient's disease, disorder, or condition hasoccurred, the dose may be adjusted for preventative or maintenancetreatment. For example, the dosage or the frequency of administration,or both, may be reduced as a function of the symptoms, to a level atwhich the desired therapeutic or prophylactic effect is maintained. Ofcourse, if symptoms have been alleviated to an appropriate level,treatment may cease. Patients may, however, require intermittenttreatment on a long-term basis upon any recurrence of symptoms.

In addition, Compound 3 may be used in combination with additionalactive compounds in the treatment of the above conditions. Theadditional compounds may be coadministered separately with Compound 3 orincluded with such an agent as an additional active ingredient in apharmaceutical composition according to the invention. In anillustrative embodiment, additional active compounds are those that areknown or discovered to be effective in the treatment of conditions,disorders, or diseases mediated by histamine H₄ receptor activity, suchas another histamine H₄ receptor modulator or a compound active againstanother target associated with the particular condition, disorder, ordisease. The combination may serve to increase efficacy (e.g., byincluding in the combination a compound potentiating the potency oreffectiveness of an agent according to the invention), decrease one ormore side effects, or decrease the required dose of the agent accordingto the invention.

When referring to modulating the target receptor, an “effective amount”means an amount sufficient to affect the activity of such receptor.Measuring the activity of the target receptor may be performed byroutine analytical methods. Target receptor modulation is useful in avariety of settings, including assays.

Compound 3 is used, alone or in combination with one or more otheractive ingredients, to formulate pharmaceutical compositions of theinvention. A pharmaceutical composition of the invention comprises aneffective amount of at least Compound 3. A pharmaceutically acceptableexcipient is part of some embodiments of pharmaceutical compositionsaccording to this invention.

A “pharmaceutically acceptable excipient” refers to a substance that isnot toxic, but it is biologically tolerable, or otherwise biologicallysuitable for administration to a subject, such as an inert substance,added to a pharmacological composition or otherwise used as a vehicle,carrier, or diluent to facilitate administration of a pharmaceuticalagent and that is compatible therewith. Examples of excipients includecalcium carbonate, calcium phosphate, various sugars and types ofstarch, cellulose derivatives, gelatin, vegetable oils, and polyethyleneglycols.

Delivery forms of the pharmaceutical compositions containing one or moredosage units of Compound 3 may be prepared using suitable pharmaceuticalexcipients and compounding techniques known or that become available tothose skilled in the art. The compositions may be administered in theinventive methods by a suitable route of delivery, e.g., oral,parenteral, rectal, topical, or ocular routes, or by inhalation.

The preparation may be in the form of tablets, capsules, sachets,dragees, powders, granules, lozenges, powders for reconstitution, liquidpreparations, or suppositories. Preferably, the compositions areformulated for intravenous infusion, topical administration, or oraladministration.

For oral administration, Compound 3 of the invention can be provided inthe form of tablets or capsules, or as a solution, emulsion, orsuspension. To prepare the oral compositions, Compound 3 may beformulated to yield an amount of free base equivalent dosage of, e.g.,from about 0.05 to about 50 mg/kg daily, or from about 0.05 to about 20mg/kg daily, or from about 0.1 to about 10 mg/kg daily, most preferably3 mg/day, 10 mg/day or 30 mg/day.

Oral tablets may include the agent and any other active ingredientsmixed with compatible pharmaceutically acceptable excipients such asdiluents, disintegrating agents, binding agents, lubricating agents,sweetening agents, flavoring agents, coloring agents and preservativeagents. Suitable inert fillers include sodium and calcium carbonate,sodium and calcium phosphate, lactose, starch, sugar, glucose, methylcellulose, magnesium stearate, mannitol, sorbitol, and the like.Examples of liquid oral excipients include ethanol, glycerol, water, andthe like. Starch, polyvinyl-pyrrolidone (PVP), sodium starch glycolate,microcrystalline cellulose, and alginic acid are examples ofdisintegrating agents. Binding agents may include starch and gelatin.The lubricating agent, if present, may be magnesium stearate, stearicacid or talc. If desired, the tablets may be coated with a material suchas glyceryl monostearate or glyceryl distearate to delay absorption inthe gastrointestinal tract, or may be coated with an enteric coating.

In some embodiments of the invention, tablets are in the form of coatedtablets, and they contain Compound 3 tabletted with a filler/binder,that in some embodiments is silicified microcrystalline cellulose orcolloidal silicon dioxide in amounts ranging from about 65.5 mg/tabletto about 190.4 mg/tablet, a filler that in some embodiments is mannitolin amounts ranging from about 21.0 mg/tablet to about 63 mg/tablet, aglidant, that in some embodiments is silica colloidal anhydrous inamounts ranging from about 0.3 mg/tablet to about 0.9 mg/tablet, alubricant that in some embodiments is magnesium stearate in amountsranging from about 1.5 mg/tablet to about 4.5 mg/tablet, and a filmcoating agent, that in some embodiments is opadry white II 85F18422 inamounts ranging from about 3.0 mg/tablet to about 9.0 mg/tablet. Amountsof Compound 3 in embodiments of such tablets are 4.124 mg, 13.747 mg,and 41.241 mg, or amounts that correspond to free base equivalentamounts of 3 mg, 10 mg, and 30 mg.

Capsules for oral administration include hard and soft gelatin capsules.To prepare hard gelatin capsules, active ingredient may be mixed with asolid, semi-solid, or liquid diluent. Soft gelatin capsules may beprepared by mixing the active ingredient with water, an oil such aspeanut oil or olive oil, liquid paraffin, a mixture of mono anddi-glycerides of short chain fatty acids, polyethylene glycol 400, orpropylene glycol.

Liquids for oral administration may be in the form of suspensions,solutions, emulsions or syrups or may be lyophilized or presented as adry product for reconstitution with water or other suitable vehiclebefore use. Such liquid compositions may optionally contain:pharmaceutically-acceptable excipients such as suspending agents (forexample, sorbitol, methyl cellulose, sodium alginate, gelatin,hydroxyethylcellulose, carboxymethylcellulose, aluminum stearate gel andthe like); non-aqueous vehicles, e.g., oil (for example, almond oil orfractionated coconut oil), propylene glycol, ethyl alcohol, or water;preservatives (for example, methyl or propyl p-hydroxybenzoate or sorbicacid); wetting agents such as lecithin; and, if desired, flavoring orcoloring agents.

Compound 3 may also be administered by non-oral routes. For example, thecompositions may be formulated for rectal administration as asuppository. For parenteral use, including intravenous, intramuscular,intraperitoneal, or subcutaneous routes, Compound 3 may be provided insterile aqueous solutions or suspensions, buffered to an appropriate pHand isotonicity or in parenterally acceptable oil. Suitable aqueousvehicles include Ringer's solution and isotonic sodium chloride. Suchforms may be presented in unit-dose form such as ampules or disposableinjection devices, in multi-dose forms such as vials from which theappropriate dose may be withdrawn, or in a solid form or pre-concentratethat can be used to prepare an injectable formulation. Illustrativeinfusion doses range from about 1 to 1000 μg/kg/minute of agent, admixedwith a pharmaceutical carrier over a period ranging from several minutesto several days.

For topical administration, the Compound 3 may be mixed with apharmaceutical carrier at a concentration of about 0.1% to about 10% ofdrug to vehicle. Another mode of administering Compound 3 may utilize apatch formulation to affect transdermal delivery.

Administration of Compound 3 according to methods of this invention maybe made by inhalation, via the nasal or oral routes, e.g., in a sprayformulation also containing a suitable carrier.

It is envisaged that Compounds 4 and 5 can also be adminstered asCompounds 3, 2.1 and 2.2 according to methods of use of this invention.

Examples of chemical entities useful in methods of the invention willnow be described by reference to illustrative synthetic schemes fortheir general preparation below and the specific examples that follow.Those of ordinary skill in the art will recognize that, to obtain thevarious compounds herein, starting materials may be suitably selected sothat the ultimately desired substituents will be carried through thereaction scheme with or without protection as appropriate to yield thedesired product. Alternatively, it may be necessary or desirable toemploy, in the place of the ultimately desired substituent, a suitablegroup that may be carried through the reaction scheme and replaced asappropriate with the desired substituent.

In the Schemes depicted below, one of ordinary skill in the art willrecognize that R⁶ may be H or a suitable nitrogen protecting group, suchas a tert-butoxycarbonyl group (Boc), and that protecting group replacedat a later stage in the synthesis.

Referring to Scheme A, amines A2 are commercially available or areprepared from acids A1 or alcohols A3. Coupling of acids A1 with aminesR⁶NH₂, in the presence of activating agents such asdicyclohexyl-carbodiimide, EDC/HOBt, or carbonyl diimidazole, in asolvent such as DMF or THF, provides the corresponding amides (notshown). Alternatively, acids A1 are activated to their correspondingacid chlorides and reacted with amines R⁶NH₂ in the presence of asuitable base such as triethylamine or diisopropylethylamine, in asolvent such as DCM or THF. The resulting amides are reduced to aminesA2 by a suitable reducing agent such as LiAlH₄, in a solvent such asTHF. Alcohols A3 are activated using general methods to form, forexample, alkyl halides or alkyl tosylates. Displacement with R⁶NH₂ inthe presence of a suitable base such as NaH, NaOH, triethylamine, ordiisopropylethylamine, in a solvent such as DCM or THF, provides aminesA2. Alternatively, amines A2 are prepared from alcohols A3 by reactionwith phthalimide or a suitable amino surrogate under Mitsunobuconditions. Where phthalimide is used, the free amine is revealedthrough treatment with hydrazine.

Referring to Scheme B, amines A2 are reacted with pyrimidines B1, whichare commercially available or are prepared by oxidation of commerciallyavailable alkylsulfanyl pyrimidines, or by other general methods, in asolvent such as pyridine, DMF, MeOH, or EtOH, or a mixture thereof, attemperatures between about room temperature and the reflux temperatureof the solvent, or in a sealed tube at temperatures up to about 120° C.In B4 and B5, R² may be H or F and R³ may be CH₃ or H.2-Aminopyrimidines B2 are converted to aldehydes B3 by reduction of theY substituent with a suitable reducing agent such as diisobutylaluminumhydride. Where Y is an ester group, reduction produces aldehydes B3 orthe corresponding alcohols (not shown). Where an alcohol is produced,oxidation using a suitable oxidizing agent such as MnO₂, Dess-Martinperiodinane, or Swern conditions, provides aldehydes B3. Condensation ofaldehydes B3 with suitably substituted diamines B4, in the presence of adehydrating agent such as NaH₂S₂O₅, in a solvent such as DMF, MeOH, orEtOH, or a mixture thereof, at temperatures between about roomtemperature and the reflux temperature of the solvent, producescompounds of Formula B5.

In addition to synthetic methodologies for preparing compound B22 asdescribed in Scheme B, other methodologies have been described in, forexample, US patent application publication US2010/0004450, U.S. Pat. No.8,309,720, which is incorporated by reference herein in its entirety.For illustrative nonlimiting purposes, see examples 7, 10, 12, 16, 24and 25 in such publication. An alternative procedure for the preparationof B22, employs compounds A21 and B11 in a bi-phasic solvent system suchas toluene and water along with a base such as K₂CO₃ with heating to atemperature of about 60-65° C. as shown in Scheme B.1. In an embodimentof this reaction, compound A21 in an aqueous solution of 10% K₂CO₃ isadded to a solution of B11 in a solvent such as toluene. The reactionmixture of A21 and B11 is heated to a temperature between 60° C. and 65°C. In a subsequent step, after heating for approximately 20 min at atemperature between 60-65° C., the aqueous portion is removed, asolution of 1N NaOH_((aq)) is added and heated to temperature between60-65° C. for approximately 10 minutes. The NaOH_((aq)) solution isremoved and water added and heated to a temperature between 60-65° C.for approximately 10 minutes. In a subsequent step, the water solutionis removed and the remaining organic solvent is removed by distillation.Compound B22 is optionally purified by recrystallization from a solventsuch as toluene.

An alternative procedure for performing Scheme B is outlined in SchemeB.2. Compound B33 according to this scheme is not isolated. Themethodology according to this scheme employs compound B22, a catalystwhich is a fine grained solid composed mostly of nickel derived from anickel-aluminum alloy, such as Raney nickel, and hydrogen gas in asolvent such as aqueous acetic acid at a temperature between 20-40° C.Embodiments of this methodology use substoichiometric amounts of suchcatalyst. This is an advantageous feature, for the presence of astoichiometric amount of catalyst is not a determining feature in thismethodology. Many processes that use the same catalyst rely on itspresence in stoichiometric amounts of such catalyst. Another feature ofthis methodology is the use of succinic anhydride, which permits asubstantial removal of impurity I1. Compound B22 is reduced byhydrogenation with a catalyst as indicated above. When suchhydrogenation is complete, as judged by there being less than about 3%of compound B22 remaining, the catalyst is removed by filtration and thefiltrate neutralized to pH=7 with an aqueous K₂CO₃ solution (50% w/w).Subsequently, succinic anhydride is added, and an organic solvent, suchas toluene for example, is added. A bi-phasic organic-aqueous medium isthus formed. In an envisaged alternative embodiment that would also leadto a bi-phasic organic-aqueous medium, succinic anhydride is dissolvedin an organic solvent, which then is added to the aqueous medium. Suchanhydride derivatizes an impurity. In a subsequent step, the pH of thesolution is adjusted to about 9.5 with an appropriate base. In someembodiments such pH adjustment was performed with an aqueous K₂CO₃solution (50% w/w) followed by heating to a temperature of about 35° C.for approximately 15-30 minutes. Phase-separation of the organic layeris performed afterwards. The organic portion of the reaction mixture iscollected, the aqueous portion is optionally re-extracted with a solventsuch as toluene, and the organic portion resulting from the secondextraction, when such second extraction is performed, is combined withthe first organic portion. In a subsequent step the organic portion iscooled to a temperature between 15-25° C. and the pH adjusted to about3.5-4 with an appropriate acid. In some embodiments, such pH adjustmentwas performed by the addition of an 8% aqueous HCl solution. In asubsequent step, the organic and aqueous portions are separated, and theaqueous portion contains compound B33.

In a separate vessel, sodium sulfite, 1,2-diamino-3,5-dimethylbenzenedihydrochloride and water are stirred at room temperature. Hydrochloricacid is added and the reaction is heated to 50° C. within 20 minutes.Air flow is circulated through the solution. Compound B33 in aqueoussolution, is added to this medium over 1.5 h to form a reaction mixturethat contains the reaction product of compound B33 and thediamino-dimethylbenzene. The reaction mixture is heated to a temperatureof about 55-60° C. for approximately 1-2.5 h. In a subsequent step, thesolids are filtered off and 2-methyltetrahydrofuran is added to thefiltrate. In a subsequent step, 30% NaOH_((aq)) is added to adjust thepH to approximately 9.5-11.5. The reaction mixture is heated to 45-50°C. for 15 min. A series of extraction steps are performed afterwards.The aqueous layer is removed and discarded, and water and 30%NaOH_((aq)) are added to the organic layer, thus forming a bi-phasicmedium, which is heated to 45-50° C. for 5-15 min. The aqueous layerfrom this bi-phasic medium is removed and discarded, and water is addedto the remaining organic layer, thus forming another bi-phasic medium,which is then heated to 45-50° C. for 5-15 min. The aqueous layer fromsuch medium is removed and discarded, and cyclohexane added and theorganic layer, which is heated to 45-50° C., and then solid Compound 2is obtained by cooling such organic layer to 0-5° C., out of whichCompound 2 crystallizes and is isolated by filtration.

Referring to Scheme C, acids A1 or alcohols A3 may be coupled with2-aminopyrimidines C1 using the methods described in Scheme A to formamides (not shown) and amines C2. The amides and compounds C2 areprocessed as described in Scheme B to provide compounds of Formula B5.

Additional synthetic methods are described in U.S. Pat. Nos. 7,507,737and 8,309,720, which are hereby incorporated by reference. Additionalsynthetic methods are described in U.S. Pat. Appl. Publ. 2010/0029942.

Additional synthetic methods can be designed from the descriptionprovided in U.S. Pat. Appl. Publ. 2005/0070550 (U.S. Pat. No.7,432,378), which is hereby incorporated by reference.

The following examples are provided to further illustrate aspects of theinvention and various preferred embodiments.

In obtaining the compounds described in the examples below and thecorresponding analytical data, the following experimental and analyticalprotocols were followed unless otherwise indicated.

Unless otherwise stated, reaction mixtures were magnetically stirred atroom temperature (rt). Where solutions are “dried,” they are generallydried over a drying agent such as Na₂SO₄ or MgSO₄. Where mixtures,solutions, and extracts were “concentrated”, they were typicallyconcentrated on a rotary evaporator under reduced pressure.

Thin-layer chromatography was performed using Merck silica gel 60 F₂₅₄2.5 cm×7.5 cm, 250 μm or 5.0 cm×10.0 cm, 250 μm pre-coated silica gelplates.

Normal-phase flash column chromatography (FCC) was performed on silicagel (SiO₂) eluting with 2 M NH₃ in MeOH/DCM, unless otherwise noted.

Mass spectra (MS) were obtained on an Agilent series 1100 MSD usingelectrospray ionization (ESI) in positive mode unless otherwiseindicated. Calculated (calcd.) mass corresponds to the exact mass.

Nuclear magnetic resonance (NMR) spectra were obtained on Bruker modelDRX spectrometers. The format of the ¹H NMR data below is: chemicalshift in ppm downfield of the tetramethylsilane reference (multiplicity,coupling constant J in Hz, integration).

Powder X-ray diffraction characterizations of compounds exemplifiedherein were performed by using a variety of X ray sources anddiffractometers as indicated below.

Powder X-ray diffraction profiles and associated data of compound 2.2,which are shown in FIG. 1, and whose data are presented in Tables 2 and2.1, were performed on an APD 2000 Diffraktometer (G.N.R. s.r.l., AgrateConturbia, Italy) equipped with a NaI scintillation counter. Sampleswere scanned from 3° to 40° 2θ at a step size of 0.01° and a time perstep of 5 seconds. The tube voltage and current were 40 kV and 30 mA,respectively. The samples were placed onto zero background aluminumholders.

Synchrotron powder X-ray diffraction measurements and associated data ofcompound 3, which are shown in FIG. 4 and whose data are presented inTables 5, 6, 6.1, 6.2 and 6.3, were performed at the Materials Sciencebeam line of the Swiss Light Source (SLS) at the Paul Scherrer Institute(PSI) in Villigen (Switzerland). Samples were measured in spinning glasscapillaries with a diameter of 1.0 mm at T=295K. The wavelength of theradiation used for the experiment was determined from a silicon powdermeasurement and refinement: λ=(1.000180±0.000051) Å,energy=(12.395773±0.000627) keV, 2θ offset=(+0.001474±0.000032)°;detector: micro strip; temperature control: cryojet; a robot system wasused for mounting the capillaries. The recorded powder profiles werepre-processed at the PSI and then transformed to the CuK<α> wavelengthscale (λ=1.5418 Å).

As to FIG. 9, powder X-ray diffraction profiles shown therein wereobtained by using an X-ray diffractometer equipped with a copper source(Cu/K_(a) 1.54056 Å). Examples of such diffractometers include theBruker AXS D8 Discover X-ray Diffractometer and the Rigaku D/Max RapidX-ray Diffractometer. The Bruker AXS D8 Discover X-ray Diffractometer isequipped with GADDS™ (General Area Diffraction Detection System), aBruker AXS HI-STAR Area Detector at a distance of 15.05 cm as per systemcalibration, automated x-y-z stage, and 0.5 mm collimator. The sample iscompacted into pellet form and mounted on the x-y-z stage. Adiffractogram is acquired (control software: GADDS™ for WNT v4.1.14,©Bruker AXS, 1997-2003) under ambient conditions at a power setting of40 kV and 40 mA in reflection mode while the sample remains stationary.The exposure time is typically 5 minutes. The diffractogram obtainedundergoes a spatial remapping procedure to account for the geometricalpincushion distortion of the area detector, then it is integrated alongchi from −118.8 to −61.8° and 2-theta 2.1-37° at a step size of 0.02°with normalization set to bin normalize. In addition to using Jadesoftware, diffraction patterns obtained on the Bruker machine are viewedusing EVA software (Analysis software: Diffract^(Plus) EVA, version 9.0,©Bruker AXS, 2003). The Rigaku D/Max Rapid X-ray Diffractometer isequipped with a manual x-y stage, and 0.3 mm collimator. The sample isloaded into a 0.3 mm boron rich glass capillary tube (Charles SupperCompany, 15 Tech Circle, Natick, Mass. 01760-1024) by sectioning off oneend of the tube and tapping the open, sectioned end into a bed ofsample. The loaded capillary is mounted in a holder that was securedinto the x-y stage. A diffractogram is acquired under ambient conditionsat a power setting of 46 kV at 40 mA in reflection mode, whileoscillating about the omega-axis from 0-5° at 1°/sec and spinning aboutthe phi-axis at 2°/sec (Control software: RINT Rapid Control Software,Rigaku Rapid/XRD, version 1.0.0, ©Rigaku Co., 1999). The exposure timeis typically 5 minutes. The diffractogram obtained is integrated over2-theta from 2-40 degrees and chi (1 segment) from 0-360° at a step sizeof 0.02° using the cylint utility in the RINT Rapid display softwareprovided with the instrument (Analysis software: RINT Rapid displaysoftware, version 1.18, ©Rigaku Co., 1999). The dark counts value is setto 8 as per the system calibration; normalization is set to average; theomega offset is set to 180°; and no chi or phi offsets are used for theintegration. Diffraction patterns are viewed using Jade software, whichis used to remove the background from the patterns and to assign peakpositions (Analysis software: Jade, version 5.0 and 6.0, ©MaterialsData, Inc., 1995-2004).

Differential Scanning calorimetry (DSC) experiments were run as follows:An aliquot of a sample was weighed into an aluminum sample pan, (panpart #900793.901; lid part #900794.901; TA Instruments, 109 LukensDrive, New Castle, Del. 19720), which was sealed by crimping. The samplepan was loaded into the apparatus (Q1000 Differential Scanningcalorimeter, TA Instruments, 109 Lukens Drive, New Castle, Del. 19720).A thermogram was obtained by individually heating the sample at a rateof 10° C./min from T_(min) (typically room temperature) to T_(max)(typically 300° C.) using an empty aluminum hermetic pan as a reference.The control software for both the DSC and TGA experiments was theAdvantage for QW-Series, version 1.0.0.78, Thermal Advantage Release2.0, ©TA Instruments-Water LLC, 2001. Dry nitrogen (compressed nitrogen,grade 4.8, BOC Gases, 575 Mountain Avenue, Murray Hill, N.J. 07974-2082)was used as a sample purge gas and was set at a flow rate of 50 mL/min.Thermal transitions were viewed and analyzed using the analysis softwareprovided with the instrument (Analysis Software: Universal Analysis 2000for Windows 95/95/2000/NT, version 3.1E; Build 3.1.0.40, ©TAinstruments-Water LLC, 1991-2001).

Thermogravimetric Analysis (TGA) experiments were run as follows: Analiquot of the sample was transferred into a platinum sample pan (panpart #952019.906; TA Instruments, 109 Lukens Drive, New Castle, Del.19720). The pan was placed on the loading platform and was thenautomatically loaded into the apparatus (Q500 ThermogravimetricAnalyzer, TA Instruments, 109 Lukens Drive, New Castle, Del. 19720)using the control software. Thermograms were obtained by individuallyheating the sample at 10° C./min from T_(min) (typically roomtemperature) to T_(max) (typically 300° C.) under flowing dry nitrogen,with a sample purge flow rate of 60 mL/min and a balance purge flow rateof 40 mL/min. Thermal transitions (e.g., weight changes) were viewed andanalyzed by using the analysis software provided with the instrument(Analysis Software: Universal Analysis 2000 for Windows 95/95/2000/NT,version 3.1E; Build 3.1.0.40, ©TA instruments-Water LLC, 1991-2001).

Chemical names were generated by using Chem Draw (CambridgeSoft,Cambridge, Mass.).

To provide a more concise description, some of the quantitativeexpressions given herein are not qualified with the term “about”. It isunderstood that, whether the term “about” is used explicitly or not,every quantity given herein is meant to refer to the actual given value,and it is also meant to refer to the approximation to such given valuethat would reasonably be inferred based on the ordinary skill in theart, including equivalents and approximations due to the experimentaland/or measurement conditions for such given value.

Whenever a yield is given as a percentage, such yield refers to a massof the entity for which the yield is given with respect to the maximumamount of the same entity that could be obtained under the particularstoichiometric conditions. Reagent concentrations that are given aspercentages refer to mass ratios, unless indicated differently.

Example 1[5-(5-Fluoro-4-methyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine

Step A; 4-Methyl-2-ethylsulfanyl-pyrimidine-5-carboxylic acid ethylester. A mixture of ethyl acetoacetate (6.37 mL, 50.0 mmol),dimethylformamide dimethylacetal (8.94 g, 75.0 mmol), and catalyticp-toluenesulfonic acid was heated at 100° C. for 2 h. After cooling tort, the mixture was diluted with 50 mL N,N-dimethylformamide (DMF) and2-ethylisothiourea hydrobromide (9.10 g, 50.0 mmol) was added. Afterheating the at 100° C. for 18 h, the mixture was cooled to rt andconcentrated to give a crude residue, which was purified by FCC(EtOAc/hexanes) to give 7.1 g (61%) of a solid. ¹H NMR (CDCl₃):8.97-8.91 (m, 1H), 4.43-4.35 (m, 2H), 3.24-3.15 (m, 2H), 2.81-2.72 (m,3H), 1.47-1.35 (m, 6H).

Step B; 2-Ethanesulfonyl-4-methyl-pyrimidine-5-carboxylic acid ethylester. To a 0° C. solution of4-methyl-2-ethylsulfanyl-pyrimidine-5-carboxylic acid ethyl ester (3 g,13.3 mmol) in 50 mL dichloromethane (DCM) was added urea hydrogenperoxide (5.20 g, 55.7 mmol) followed by trifluoroacetic anhydride (7.39mL, 53.1 mmol) dropwise. The solution was warmed to rt for 2 h beforequenching with saturated Na₂S₂O_(3(aq)) (20 mL) and extracting with DCM(100 mL). The organic layer was dried (Na₂SO₄) and concentrated to give1.50 g of an orange solid which was used immediately in the next stepwithout purification. ¹H NMR (CDCl₃): 9.28 (s, 1H), 4.47 (q, J=7.2 Hz,2H), 3.60 (q, J=7.5 Hz, 2H), 2.96 (s, 3H), 1.47-1.42 (m, 6H).

Step C;4-Methyl-2-[3-(1-methyl-piperidin-4-yl)-propylamino]-pyrimidine-5-carboxylicacid ethyl ester. A mixture of2-ethanesulfonyl-4-methyl-pyrimidine-5-carboxylic acid ethyl ester (0.30g, 1.18 mmol) and 3-(1-methyl-piperidin-4-yl)-propylamine (0.18 mg, 1.10mmol) in EtOH (3 mL) was heated in a sealed tube at 100° C. for 6 h. Themixture was concentrated and purified by FCC to give 200 mg (53%). ¹HNMR (CDCl₃): 8.88-8.72 (m, 1H), 5.60-5.44 (m, 1H), 4.31 (q, J=7.2 Hz,2H), 3.52-3.39 (m, 2H), 2.91-2.77 (m, 2H), 2.64 (s, 3H), 2.26 (s, 3H),1.94-1.85 (m, 2H), 1.72-1.57 (m, 4H), 1.41-1.20 (m, 8H).

Step D;{4-Methyl-2-[3-(1-methyl-piperidin-4-yl)-propylamino]-pyrimidin-5-yl}-methanol.To a 0° C. solution of4-methyl-2-[3-(1-methyl-piperidin-4-yl)-propylamino]-pyrimidine-5-carboxylicacid ethyl ester (0.20 g, 0.63 mmol) in THF (6 mL) was addeddiisobutylaluminum hydride (1 M in hexanes; 1.25 mL, 1.25 mmol)dropwise. The mixture was warmed to rt over 1 h. The reaction wasquenched with 1 M H₂SO₄ (2 mL). The mixture was neutralized withsaturated NaHCO_(3(aq)) and diluted with MeOH (2 mL), CHCl₃ (10 mL), andsatd. aq. sodium potassium tartrate (10 mL). The mixture was stirredvigorously until the layers separated. The organic layer was dried(Na₂SO₄) and concentrated to give the crude product (138 mg), which wasused in the next step without further purification. ¹H NMR (CDCl₃): 8.07(s, 1H), 4.52 (s, 2H), 3.42-3.33 (m, 2H), 2.88-2.74 (m, 2H), 2.41 (s,3H), 2.23 (s, 3H), 1.93-1.83 (m, 2H), 1.72-1.53 (m, 4H), 1.35-1.16 (m,5H).

Step E;[5-(5-Fluoro-4-methyl-1H-benzoimidazol-2-yl)-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine.To a mixture of4-methyl-2-[3-(1-methyl-piperidin-4-yl)-propylamino]-pyrimidin-5-yl}-methanol(0.14 g, 0.49 mmol) in toluene (3 mL) was added MnO₂ (0.22 g, 2.48mmol). After 30 min at 70° C., the mixture was filtered throughdiatomaceous earth. The filtrate was concentrated and immediatelydissolved in DMF. A portion of this solution (corresponding to 0.05 g,0.17 mmol of4-methyl-2-[3-(1-methyl-piperidin-4-yl)-propylamino]-pyrimidine-5-carbaldehyde)was then treated with 4-fluoro-3-methyl-benzene-1,2-diamine (1.1 equiv.)and Na₂H₂S₂O₅ (1.25 equiv.) at 90° C. for 12 h. The reaction mixture waspurified by FCC to afford the title compound. MS: mass calcd. forC₂₂H₂₉FN₆, 396.24; m/z found, 397.2 [M+H]⁺. ¹H NMR (CD₃OD): 8.62 (s,1H), 7.55 (dd, J=8.0, 3.9 Hz, 1H), 7.17 (dd, J=10.3, 8.8 Hz, 1H), 3.60(t, J=6.9 Hz, 2H), 3.10-2.99 (m, 2H), 2.71 (s, 3H), 2.66 (d, J=1.4 Hz,3H), 2.44 (s, 3H), 2.26-2.17 (m, 2H), 1.98-1.88 (m, 2H), 1.87-1.77 (m,2H), 1.55-1.36 (m, 5H).

In some embodiments Compound 2, shown in Example 2, was synthesizedanalogously to the procedures described in Example 1.

Example 2[5-(4,6-Dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine

MS: mass calcd. for C₂₃H₃₂N₆, 392.27; m/z found, 393.3 [M+H]⁺. ¹H NMR(CD₃OD): 8.43 (s, 1H), 7.20 (s, 1H), 6.89 (s, 1H), 3.41 (t, J=7.0 Hz,2H), 2.89-2.82 (m, 2H), 2.54 (s, 3H), 2.53 (s, 3H), 2.42 (s, 3H), 2.25(s, 3H), 2.05-1.96 (m, 2H), 1.78-1.70 (m, 2H), 1.69-1.59 (m, 2H),1.34-1.21 (m, 5H).

Example 3 Preparation of5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)-propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate (1:0.5), polymorph A, Compound 2.1

The preparation of4-methyl-2-((3-(1-methylpiperidin-4-yl)propyl)amino)pyrimidine-5-carbonitrilewas described in Schemes 1, 2, 3 and 4 and examples 7, 10, 12, 16, 24and 25 in U.S. Pat. No. 8,309,720, all of which are incorporated hereinby reference.

An alternative procedure for the preparation of4-methyl-2-((3-(1-methylpiperidin-4-yl)propyl)amino)pyrimidine-5-carbonitrileused in the preparation of Compound 2.1 is as follows. To a solution of4-methyl-2-(methylsulfonyl)pyrimidine-5-carbonitrile (21.64 g, 109.7mmol) in toluene (260 g) was added3-(1-methylpiperidin-4-yl)propan-1-amine (14.30 g, 91.5 mmol) in 10%K₂CO_(3(aq)) (110.2 g, 100 mL). The reaction was heated to 60-65° C. for20 minutes. The aqueous layer was then removed and to the organic layerwas added 1M NaOH (110.1 g). The mixture was reheated to 65° C., stirredfor 10 minutes and the aqueous layer was removed. To the organic layer,water (110.8 g) was added and the solution reheated to 65° C. for 10minutes. The aqueous layer was removed and the organic layer wasconcentrated under reduced pressure.4-methyl-2-((3-(1-methylpiperidin-4-yl)propyl)amino)pyrimidine-5-carbonitrilewas then crystallized from a solution of toluene (approximately 65 g) ata temperature of about 65° C. to provide 21.20 g of4-methyl-2-((3-(1-methylpiperidin-4-yl)propyl)amino)pyrimidine-5-carbonitrile.

Step A

A 100 L glass-lined reactor was charged with4-methyl-2-((3-(1-methylpiperidin-4-yl)propyl)amino)pyrimidine-5-carbonitrile(5.41 kg, 19.8 mol) and toluene (47.13 kg). The resultant suspension wasstirred and cooled to about 0 to −5° C. Next, 1.0 M diisobutylaluminumhydride (DIBAL-H) in toluene (40.55 kg, 47.33 mol) was added, vianitrogen pressure, while maintaining the internal reaction temperatureat <2° C. After completing the addition, the resultant reaction solutionwas warmed to about 5-10° C. and the reaction monitored for completionby HPLC. Cold ethyl acetate (4.89 kg) was then added over 30 min and theresultant mixture stirred for 15-20 minutes. The resultant mixture(containing4-methyl-2-((3-(1-methylpiperidin-4-yl)propyl)amino)pyrimidine-5-carbaldehyde)was transferred to a 100 L glass receiver and rinsed with toluene (1.00kg).

An alternative procedure to prepare4-methyl-2-((3-(1-methylpiperidin-4-yl)propyl)amino)pyrimidine-5-carbaldehydeis as follows.4-methyl-2-((3-(1-methylpiperidin-4-yl)propyl)amino)pyrimidine-5-carbonitrile(“compound 1-E-2”) was dissolved in acetic acid (1.32 kg per kg ofcompound 1-E-2). A catalyst which is a fine grained solid composedmostly of nickel derived from a nickel-aluminum alloy, such as Raneynickel, type 3202, (55% w/w suspension in water, 0.29 g per g ofcompound 1-E-2) was added and the reaction was placed under anatmosphere of H₂, (p(H₂)=1-1.3 bar) at T=25° C. When the reaction wascomplete as judged by there being not more than about 3% of compound1-E-2 remaining, the reaction mixture was filtered and the filtrateneutralized to pH=7 with aqueous potassium carbonate (50% w/w) solution.Succinic anhydride (0.185 g per g of initial amount of compound 1-E-2)was added. Toluene (4.5 g per g of initial amount of compound 1-E-2) wasadded and additional aqueous potassium carbonate 50% was added to adjustthe pH of the solution to pH>9, in some embodiments to pH=9.5. Thelayers in such bi-phasic organic-aqueous medium were separated and theaqueous layer was washed once with toluene (0.5 g per g of initialamount of compound 1-E-2). The united organic layers were then extractedwith an aqueous solution at a pH of equal to or less than about 4, insome embodiments at pH of about 3.5. In some embodiments, such solutionwas an 8% aqueous HCl solution (1.01 g per g of initial amount ofcompound 1-E-2). This aqueous phase, containing4-methyl-2-((3-(1-methylpiperidin-4-yl)propyl)amino)pyrimidine-5-carbaldehyde,was used without further work-up in the next step A-1. The so-preparedcarbaldehyde solution could be used in further steps to preparecompounds according to this invention, such as compounds 2, 2.1 and 3.

STEP A-1. In some embodiments, in a separate vessel sodium sulfite (1.2equivalents (eq) relative to the initial amount of compound 1-E-2),1,2-diamino-3,5-dimethylbenzene dihydrochloride (1.2 equivalents (eq)relative to the initial amount of compound 1-E-2) and water (5.74 g perg of the initial amount of compound 1-E-2) were stirred at roomtemperature. Hydrochloric acid (37%, 0.24 g per g of the initial amountof compound 1-E-2) was added and the reaction was heated to 50° C.within 20 minutes and air flow was circulated through the solution.Compound B33 in aqueous solution, prepared for example as indicatedabove, was added to this reaction mixture over 1.5 h. The reaction washeated to a temperature of about 55-60° C. for approximately 1-2.5 h. Ina subsequent step, the solids were filtered off and2-methyltetrahydrofuran (7.18 g per g of the initial amount of compound1-E-2) was added to the filtrate. In a subsequent step, 30% NaOH_((aq))(1.1-1.2 g per g of the initial amount of compound 1-E-2) was added toadjust the pH to approximately 9.5-11.5. The reaction mixture was heatedto 45-50° C. for 15 min. The aqueous layer was removed, and water (0.65g per g of the initial amount of compound 1-E-2) and 30% NaOH_((aq))(0.18 g per g of the initial amount of compound 1-E-2) was added to theorganic layer, which was heated to 45-50° C. for 5-15 min. The aqueouslayer in the resulting bi-phasic medium was removed and discarded, andwater (0.62 g per g of the initial amount of compound 1-E-2) was addedto the organic layer thus forming another bi-phasic medium, which washeated to 45-50° C. for 5-15 min. The aqueous layer from such bi-phasicmedium was removed and discarded, cyclohexane added to the organiclayer, which was heated to 45-50° C., and solid Compound 2 was obtainedby cooling it to 0-5° C., crystallizing Compound 2 out of it, andisolating it by filtration.

Step B

A cold solution of water/sulfuric acid (27.05 kg/2.26 kg) was added toeach, a 100 L Hastelloy reactor and a 100 L glass lined reactor. Theresultant aqueous acid solutions were stirred and cooled to about 2-5°C. Maintaining the temperature <30° C. at all times, 50% (by volume) ofthe mixture prepared in STEP A above was added to each aqueous sulfuricacid solution. The resultant suspension was checked for pH (target pH of4-5) and stirred at about 20-25° C. for about 1.5-2 h. The suspensionswere then cooled to about 10-15° C. and the pH of the suspensionsadjusted to pH˜11-12, by adding 6N sodium hydroxide (16.12 kg, 81.42mol), over 20 min. The resultant mixtures were then stirred for anadditional 15-20 minutes, the agitation was then stopped and the phasesallowed to separate.

The organic phases were removed from the top of each reactor via vacuumand combined. Then the aqueous phase and middle oil phases were drainedvia the bottom valve of each reactor and discarded. The combined organicphase was concentrated at ˜40° C. to yield a solid. This solid wastransferred to drying trays and dried (60 Torr, 30-35° C.) overnight toyield solid4-methyl-2-((3-(1-methylpiperidin-4-yl)propyl)amino)pyrimidine-5-carbaldehyde.

Step C

In a 100 L glass-lined reactor, sodium metabisulfite (Na₂S₂O₅) (1.96 kg,9.79 mol) was dissolved in purified water (54.63 kg), followed by theaddition of 3,5-dimethyl-1,2-benzenediamine-2HCl (2.07 kg, 9.86 mol) andthe resultant mixture stirred at about 20-25° C. to effect solution.Next, concentrated hydrochloric acid (1.65 kg, 16.79 mol) was added,followed by addition of4-methyl-2-((3-(1-methylpiperidin-4-yl)propyl)amino)pyrimidine-5-carbaldehyde,prepared as in STEP B above (2.74 kg, 9.79 mol) and the resultantmixture stirred at about 23-27° C. to effect solution. The resultantmixture was heated to about 57-62° C. and monitored for completion byHPLC. The reaction mixture was cooled to about 20-25° C. and then halfof the volume (˜30 L) was then added, via a metering pump, to a stirring50 L glass reactor system containing a solution of potassium carbonate(3.9 kg, 28.2 mol) dissolved in purified water (15 kg), resulting in theformation of a precipitate. The precipitated product was stirred for ˜1h and then allowed to settle. The clear supernatant (˜20 L) was removedfrom the top of the 50 L reactor system and purified water (˜20 kg) wasadded. The resultant mixture was stirred for 10 min, filtered, washedwith water (13 kg) and dried at 35-40° C. under vacuum to yield solid[5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine,compound 2. MS: [M+H]⁺=393, ¹H NMR (600 MHz, Methanol-d₆) δ, 1.38-1.43(m, 2H), 1.43-1.52 (m, 2H), 1.53-1.61 (br m, 1H), 1.64-1.71 (m, 2H),1.90-1.96 (br m, 2H), 2.42 (s, 3H), 2.53 (s, 3H), 2.54 (s, 3H), 2.74 (s,3H), 2.78-2.86 (br m, 2H), 3.15-3.36 (m, 2H), 3.36-3.47 (m, 2H) 4.35 (s,1H), 6.90 (s, 1H), 7.20 (s, 1H), 8.44 (br s, 1H).

Step D Preparation of Hemi-Tartrate of[5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine

In a 100 L Hastelloy reactor,[5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine,prepared as indicated above (6.58 kg, 15.56 mol) was dissolved in amedium containing at least one low-alkyl alcohol, which in an embodimentwas denatured ethanol (31.00 kg), at about 48-52° C., denatured ethanolbeing 95:5 (volume ratio) ethanol:2-propanol mixture.

After stirring for 15 minutes, the resultant hazy solution was cooled toabout 25-30° C. Magnesium sulfate (0.60 kg) was added and the resultantmixture was stirred an additional 30 minutes. The magnesium sulfate wasfiltered over CELITE® (0.30 kg) and the resultant clear solution (KarlFischer titration, measured water content=0.22%) was transferred to aclean 100 L glass-lined reactor and heated to about 48-52° C. A solutionof L-(+)-tartaric acid (1.16 kg, 7.73 mol) in a medium containing atleast one low-alkyl alcohol, which in an embodiment was denaturedethanol (10.0 kg) was charged to the reactor over 20 minutes. Theresultant hemitartrate salt alcohol mixture was heated to about 70-75°C. and then aged for 1 h. The resultant yellow slurry was cooled toabout 0-5° C. over a 2 h period and then aged for 20 min. The product(as a precipitate) was filtered, washed with cold denatured ethanol(5.20 kg), then dried at about 75-80° C. under vacuum to yield the[5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine,as its corresponding hemi-tartrate solid salt, compound 2.1. Becausemore than one crystallization is performed according to this invention,the crystallization referred to above for Compound 2.1 is sometimesreferred to as a first crystallization. When accompanying the termcrystallization throughout this specification, ordinal terms are usedfor reference purposes, and the use of a certain ordinal term does notnecessarily imply that the corresponding operations characterized bypreceding ordinal terms must necessarily be performed too.

Step E Recrystallization

Method E-S. In a 100 L Hastelloy reactor, the hemi-tartrate of[5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine,compound 2.1, prepared as in STEP D above (5.19 kg, 11.10 mol) wasdissolved in a low-alkyl alcohol-containing medium, which in anembodiment was a hydroalcoholic solvent, which in an embodiment was amixture of denatured ethanol (32.40 kg) and water (2.62 kg) at about75-78° C. The resultant solution was cooled to about 50-55° C. andpolish filtered (to remove any foreign particles) into a clean 100 Lglass-lined reactor, followed by a rinse with denatured ethanol (4.15kg). A solvent containing at least one low-alkyl alcohol, which in anembodiment was denatured ethanol (25.62 kg) was added and the resultantsolution was stirred and heated to about 78-80° C. to atmosphericallydistill off 51 L of the solvent. The resultant solution was cooled toabout 55-60° C. and additional solvent containing at least one low-alkylalcohol, which in an embodiment was denatured ethanol (27.63 kg) wasadded, followed by heating to about 78-80° C. to atmospherically distilloff 27 L of the solvent. The resultant solution was then cooled to about50-55° C., seeded with Compound 2.1 seeds (2.0 g, 4.3 mmol), thenfurther cooled to about 18-22° C. and then stirred for 1 h. Theresultant precipitate was filtered, washed with denatured ethanol (5.00kg) and dried at about 75-80° C. under vacuum to yield the solidhemi-tartrate of[5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine(compound 2.1); melting point 179° C.

Method E-T. An alternative procedure for the recrystallization ofcompound 2.1; hemi-tartrate of[5-(4,6-Dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine:A 500 mL-reactor was charged with[5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-aminehemi-tartrate (24.0 g, 25.7 mmol) and a low-alkyl alcohol-containingmedium, which in an embodiment was a medium containing at least one alow-alkyl alcohol, which in an embodiment was an alcohol, which in anembodiment was methanol (63.0 g). The resulting mixture was warmed to50° C. for 15 min, until all the solids were observed to dissolve. Alow-alkyl alcohol-containing medium, which in an embodiment was a mediumcontaining at least one a low-alkyl alcohol, which in an embodiment wasdenatured ethanol (105.0 g) was then added and the resulting solutionwas filtered (at 50° C.) to remove any remaining particles. The filtratewas heated briefly to reflux, then cooled to approx. 60° C., beforeseeding with crystals of Compound 2.1. The resulting mixture wassubjected to the following temperature profile for crystallization: 1 hat 60° C., cooling to 40° C. over 2 h, heating to 50° C. over 1 h,cooling to 30° C. over 2 h, heating to 40° C. over 1 h, cooling to 20°C. over 2 h, heating to 30° C. over 1 h, cooling to 10° C. over 2 h,heating to 20° C. over 1 h, then cooling to 0° C. over 2 h. Theresulting suspension was maintained at 0° C. for 7 h, then the resultingsolid precipitate was isolated by suction filtration, washed withdenatured ethanol (3×30.0 g) and dried in vacuo at 40° C. to yieldCompound, 2.1 as a white crystalline solid. FIG. 6 shows thedifferential scanning calorimetry (DSC) and thermo gravimetric analysis(TGA) profiles of Compound 2.1.

Because more than one crystallization is performed according to thisinvention, the recrystallization referred to above for Compound 2.1 issometimes referred to as a second crystallization. Whetherrecrystallized according to method E-S or E-T, the ¹H NMR of a sample ofthe anhydrous hem i-tartrate of[5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine,compound 2.1: ¹H NMR (300 MHz, Methanol-d₄) δ, 8.44 (br, s, 1H), 7.20(s, 1H), 6.90 (s, 1H), 4.35 (s, 1H), 3.35-3.48 (m, 4H), 2.76-2.89 (o, m,2H), 2.75 (s, 3H), 2.54 (s, 3H), 2.53 (s, 3H), 2.42 (s, 3H), 1.88-1.99(br, m, 2H), 1.34-1.75 (m, o, 7H).

Compound 2.1 has an aqueous solubility at room temperature of about 1.1g/ml. This compound is hygroscopic. It converts to Compound 3 at above70% relative humidity, and it forms the tetrahydrate Compound 3 inaqueous solution.

Embodiments of Compound 2.1 obtained as described in this Example 3 hadpurity equal to or about 98.95% Recrystallization produced embodimentsof the same compound with purity equal to or about 99.23%. Puritychanges upon recrystallization of Compound 2.1 are shown in Table 1.Impurities I1-I11 and A1-A19 referred to in various of the Tablespresented herein are characterized in Table 9 and its associatedchemical structures in Example 11, and also in Tables 1 and 7.

TABLE 1 Average Average Relative impurities (%) impurities (%) retentionof Compound of Compound m/z time 2.1 before 2.1 after Impurity [M + H]⁺(RRT) recrystallization recrystallization I1 or A1 278 0.32 na nd A2 2760.48 0.01 nd I3 or A3 277 0.73 nd nd A4 395 0.81 0.03 nd I5 or A5 6530.86 0.24 0.154 A6 unk 0.87 nd 0.01 A7 274/733 0.89 0.09 0.06 A8a & A8b653/unk 0.91 0.11 0.02 I8 or A9 505 0.93 0.02 0.02 A10 unk 0.95 0.030.01 A11 unk 0.97 0.02 0.01 A12 unk 0.98 0.02 0.02 Compound 2.1 393 1.0098.95 99.23 A13 unk 1.03 nd 0.01 I7 or A14 407 1.04 0.18 0.23 A15 unk1.048 nd Nd A16 unk 1.057 nd 0.01 A17 unk 1.064 0.01 0.03 A18a & A18b512/409 1.07 0.08 0.04 A19 unk 1.08 0.03 0.01 A20 unk 1.10 0.06 0.04 A21unk 1.14 0.04 Nd A22 847 1.17 0.05 0.02 Abbreviations used in theimmediately preceding Table: nd = not detected, unk = unknown, na = notanalyzed

As displayed in FIG. 6, the anhydrous form 2.1 shows an initial 0.3%weight loss up to 170° C. of the surface moisture, and subsequently theappropriate stoichiometric (0.5 mol) weight loss of tartaric acid (˜15%,16.05% theoretical). The melting point is a fairly sharp endotherm witha peak max at 184° C.

Example 4 Examples 4-1 and 4-2 Preparation of5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)-propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate (1:0.5), polymorph B, Compound 2.2, fromCompound 2.1

Example 4-1

In a 10 mL glass tube equipped with a magnetic stirring bar,5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate (1:0.5), compound 2.1 (1 g) was dissolved inwater (10 mL) at room temperature (22° C.). The clear yellowish solutionwas stirred at room temperature overnight, then cooled to 2.5° C. for 2hours, before the product was isolated by filtration and dried in vacuoovernight at 55° C. to yield 0.9 g of compound 2.2 (water content 4.9%).

Example 4-2

In other embodiments, Compound 2.2 was prepared as follows. In a 10 mLglass tube equipped with a magnetic stirring bar,5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate (1:0.5), compound 2.1 (0.5 g) was dissolved ina mixture of water (4.5 mL) and 2-propanol (0.5 mL) at 50° C. The clearyellowish solution was cooled to 10° C. within 2 hours leading tocrystallization of a white solid. The resulting thick suspension is keptat 10° C. overnight, the product is then isolated by filtration anddried in vacuo for 21 h to yield 0.43 g of compound 2.2.

The powder X-ray diffraction (XRD) pattern of an embodiment of compound2.2, Example 4.2, is shown in FIG. 1, and the XRD peak lists are shownin Tables 2 and 2.1. FIG. 8 shows the differential scanning calorimetry(DCS) and thermo gravimetric analysis (TGA) profiles of Compound 2.2.

TABLE 2 XRD Peak list for an embodiment of Compound 2.2 with relativeintensity of at least 9% Position [°2θ] d-spacing [Å] Intensity (counts)Relative Intensity (%) 6.96 12.69 186 11.1 7.67 11.52 586 34.8 8.2610.70 291 17.3 8.63 10.24 256 15.2 9.91 8.92 413 24.6 11.34 7.80 153 9.112.09 7.31 344 20.5 13.66 6.48 1682 100.0 14.73 6.01 579 34.4 16.85 5.26677 40.2 18.21 4.87 385 22.9 19.24 4.61 279 16.6 20.89 4.25 417 24.823.25 3.82 1378 81.9 23.98 3.71 611 36.3 25.04 3.55 296 17.6 26.25 3.39318 18.9

TABLE 2.1 XRD Peak list for an embodiment of Compound 2.2 with relativeintensity of at least 20% Position [°2θ] d-spacing [Å] Intensity(counts) Relative Intensity (%) 7.67 11.52 586 34.8 9.91 8.92 413 24.612.09 7.31 344 20.5 13.66 6.48 1682 100.0 14.73 6.01 579 34.4 16.85 5.26677 40.2 18.21 4.87 385 22.9 20.89 4.25 417 24.8 23.25 3.82 1378 81.923.98 3.71 611 36.3

Compound 2.2 is physically stable only when stored in a tightly sealedvial at ambient condition. It absorbs water readily and converts toCompound 3 when exposed to the atmosphere.

When purification by recrystallization of Compound 2.1 was attempted byusing alternative conditions, such as by using water:2-propanol (90:10,weight ratio) and overnight in-vacuo drying at 55° C., compound 2.1 wasexpected, but instead compound 2.2 was obtained. In another alternativerecrystallization process using water and then isolation by filtrationand in-vacuo drying for 21 h, Compound 2.2 was also obtained instead ofthe expected Compound 2.1. In contrast, recrystallization of Compound 3does not present this polymorphism generation, but it generates onesingly characterized form of the same Compound.

Example 5 Preparation of5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)-propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate tetrahydrate (1:0.5:4), Compound 3, from thefree base Compound 2

A glass reactor with mechanical stirrer was charged with5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)propyl]-2-pyrimidinamine),compound 2 (10.0 g, 25.2 mmol (assay-corrected as appropriate to thisequivalent amount depending on purity)), L-(+)-tartaric acid (1.90 g,12.5 mmol) and water (75.1 g) at 20° C. The reaction mixture was heatedto reflux until the solid was completely dissolved. The clear solutionwas then cooled to 35° C. and seeding crystals of5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)-propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate tetrahydrate (1:0.5:4), compound 3.S (preparedin Example 6) were added. After gradually cooling to 5° C. overnight,the product was isolated by suction filtration and the filter cakewashed with water (10 g). The solid was dried in vacuo (at ca. 200 mbar)with a gas bleed to yield the title Compound 3 (93.2% yield). Table 3and FIG. 2 display the impurity profiles for Compounds 2 and 3,according to this example, showing that the impurity profile of Compound3 is significantly reduced with respect to that of Compound 2.

TABLE 3 Impurity Profile for Compounds 2 and 3, (Example 5) Compound 2Compound 3 Impurity 1 (I1) 0.03 0 Impurity 2 (I2) 0 0 Impurity 3 (I3)0.04 0 Impurity 4 (I4) 0.18 0.03 Impurity 5 (I5) 0.37 0.05 Impurity 6(I6) 0.07 0 Impurity 7 (I7) 0.17 0.05 Impurity 8 (I8) 0.15 0.14 Impurity9 (I9) 0.08 0.06 Impurity 10 (I10) 0.09 0

The DSC and TGA profiles of Compound 3 (FIG. 7) show an initial 12.7%water loss before 100° C., corresponding to ˜4 mol of water (13.3%calculated) followed by a 12.8% weight loss of the tartaric acid. Themelting point is a sharp endotherm with a peak max at 97.5° C., and theendotherm at 184° C., which is characteristic of the anhydrous form, isno longer present.

Example 6 Preparation of SeedingCrystals-5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)-propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate hydrate (1:0.5:4), Compound 3.S, that wasused, for example, in the seeding described in Example 7

In a glass tube with magnetic stirring bar,(5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate (1:0.5)), compound 2.1 (crude) was dissolvedin water at 60° C. The solution was cooled to room temperature, thenstirred overnight. A yellowish suspension formed. After cooling thereaction mixture to 2.5° C. for 1.5 h, the solid was isolated byfiltration and washed with water to provide5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)-propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate hydrate (1:0.5:4), Compound 3.S.

Example 7 Preparationof-5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)-propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate hydrate (1:0.5:4), Compound 3, from theanhydrous hemitartrate, Compound 2.1

A jacketed glass reactor was charged with5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate (1:0.5), compound 2.1 (60.0 g, 121.9 mmol) andwater (280.0 g) at 20° C. The solid was dissolved by heating thereaction mixture to T 58° C. The resultant clear, yellow solution wasfiltered (polish filtration) and the filter washed with water (20.0 g).The filtrate was cooled to T 40° C. and seeded with5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate hydrate (1:0.5:4), Compound 3.S (0.01 g). Thethin suspension was stirred at T=35-40° C. for 1 h, then cooled stepwiseto 5° C., resulting in the crystallization of the product. Because morethan one crystallization is performed according to this invention, thecrystallization referred to above for Compound 3 is sometimes referredto as a third crystallization. It is sometimes referred to as a secondcrystallization if Compound 2.1 has only been crystallized once. Thewhite suspension was kept at T=5° C. for 4 h, before the product wasisolated by centrifugation. The product cake was washed with water(104.0 g). The solid was dried in vacuo (200-300 mbar) at 20-30° C. for28 h with a gas bleed to yield the title Compound 3 (95% of th. yield).This compound has an aqueous solubility of about 4.1 mg/ml at roomtemperature. It is stable under ambient conditions, but converts toCompound 2.2 upon dehydration by heating or in low relative humidity.The powder X-ray diffraction (XRD) profile of an embodiment of Compound3 is shown in FIG. 4, and the XRD peak lists are shown in Tables 5, 6and 6.1-6.3. FIG. 9 displays the XRD profiles for Compounds 2.1, 2.2 and3. Table 4 and FIG. 3 display the impurity profiles for compounds 2.1and 3, according to this example, which that, as noted with respect toCompound 2, that the impurity profile of Compound 3 is significantlyreduced with respect to that of Compound 2.1. Embodiments of Compound 3obtained as described in this Example 7 had purity equal to or about99.86%. Compound 3 presents advantageous development chemistry features:The synthesis of Compound 3 provides high, reproducible yield (about95%, compared to about 85% for Compound 2.1); it is synthesized by asimple methodology that does not require azeotropic distillation orexposure to long stirring times and heating in the presence ofMeOH/EtOH, which could lead to the formation of side products; itpresents high and reproducible purity, including the removal of certainamino impurities; and crystallization can be done in water as solvent,with no need for mother liquor incineration, which leads to cost savinggreen chemistry.

TABLE 4 Impurity Profiles of Compounds 2.1 and 3 (Example 7) Compound2.1 Compound 3 Impurity 11 (I11) 0.98 0 Impurity 1 (I1) 0 0 Impurity 2(I2) 0.07 0 Impurity 3 (I3) 0.29 0 Impurity 4 (I4) 0 0 Impurity 5 (I5)0.03 0 Impurity 6 (I6) 0.29 0 Impurity 7 (I7) 0.67 0.18 Impurity 8 (I8)0.06 0.02

TABLE 5 XRD Peak list for an embodiment of Compound 3 (Example 7) forpeaks with relative intensities >5% Position [°2θ] d-spacing [Å]Intensity (counts) Relative Intensity (%) 6.909 12.79 19018 20.7 6.96312.70 13509 14.7 8.692 10.17 92032 100.0 11.957 7.40 5763 6.3 12.1077.31 51083 55.5 12.419 7.13 6894 7.5 13.956 6.35 5038 5.5 14.463 6.126922 7.5 15.355 5.77 6205 6.7 15.393 5.76 5573 6.1 15.755 5.62 4416 4.816.304 5.44 15526 16.9 16.350 5.42 14203 15.4 17.051 5.20 6303 6.817.442 5.08 5085 5.5 18.445 4.81 7903 8.6 18.540 4.79 5021 5.5 19.2654.61 23648 25.7 19.861 4.47 10731 11.7 19.906 4.46 10331 11.2 21.6284.11 10197 11.1 21.734 4.09 79383 86.3 22.514 3.95 8529 9.3 23.115 3.854787 5.2 23.963 3.71 11967 13.0 24.052 3.70 28743 31.2 24.352 3.66 4802652.2 25.124 3.54 12475 13.6 26.434 3.37 8095 8.8 27.012 3.30 13716 14.930.257 2.95 5159 5.6 30.297 2.95 6434 7.0 30.449 2.94 7306 7.9

TABLE 6 XRD Peak list for an embodiment of Compound 3 (Example 7) forpeaks with relative intensities >10% Position [°2θ] d-spacing [Å]Intensity (counts) Relative Intensity (%) 6.909 12.79 19018 20.7 6.96312.70 13509 14.7 8.692 10.17 92032 100.0 12.107 7.31 51083 55.5 16.3045.44 15526 16.9 16.350 5.42 14203 15.4 19.265 4.61 23648 25.7 19.8614.47 10731 11.7 19.906 4.46 10331 11.2 21.628 4.11 10197 11.1 21.7344.09 79383 86.3 23.963 3.71 11967 13.0 24.052 3.70 28743 31.2 24.3523.66 48026 52.2 25.124 3.54 12475 13.6 27.012 3.30 13716 14.9

TABLE 6.1 XRD Peak list for an embodiment of Compound 3 (Example 7) forpeaks with relative intensities >50% Position [°2θ] d-spacing [Å]Intensity (counts) Relative Intensity (%) 8.692 10.17 92032 100.0 12.1077.31 51083 55.5 21.734 4.09 79383 86.3 24.352 3.66 48026 52.2

TABLE 6.2 XRD Peak list for an embodiment of Compound 3 (Example 7) forpeaks with relative intensities >20% Position [°2θ] d-spacing [Å]Intensity (counts) Relative Intensity (%) 6.909 12.79 19018 20.7 8.69210.17 92032 100.0 12.107 7.31 51083 55.5 19.265 4.61 23648 25.7 21.7344.09 79383 86.3 24.052 3.70 28743 31.2 24.352 3.66 48026 52.2

TABLE 6.3 XRD Peak list for an embodiment of Compound 3 (Example 7) forpeaks with relative intensities of at least 13% Position [°2θ] d-spacing[Å] Intensity (counts) Relative Intensity (%) 6.909 12.79 19018 20.76.963 12.70 13509 14.7 8.692 10.17 92032 100.0 12.107 7.31 51083 55.516.304 5.44 15526 16.9 16.350 5.42 14203 15.4 19.265 4.61 23648 25.721.734 4.09 79383 86.3 23.963 3.71 11967 13.0 24.052 3.70 28743 31.224.352 3.66 48026 52.2 25.124 3.54 12475 13.6 27.012 3.30 13716 14.9

Example 8 Recrystallizationof-5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)-propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate hydrate (1:0.5:4), Compound 3

In a 500 mL glass reactor equipped with a temperature probe andmechanical stirrer,5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)propyl]-2-pyrimidinamine2,3-dihydroxy-butanedioate hydrate (1:0.5:4), compound 3 (Example 5)(72.0 g, 133.4 mmol) was slurried in water (400.0 g) at 15-25° C. Thewhite suspension was then heated to 60° C. within ca. 30 min to dissolvethe solid completely. To the resultant yellowish solution was then addeda suspension of seeding crystals (0.36 g,5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)propyl]-2-pyrimidinamine2,3-dihydroxybutanedioate hydrate (1:0.5:4), compound 3.S, in 2 mLwater, stirred at 20-25° C. for 1 h). The thin suspension was kept at40° C. for approximately 1 h, then cooled stepwise to 5° C. within aminimum of 9 h. It was kept at 5° C. overnight, before the product wasisolated by centrifugation. Because more than one crystallization isperformed according to this invention, the recrystallization referred toabove for Compound 3 is sometimes referred to as a fourthcrystallization. It is sometimes referred to as a third crystallizationwhen Compound 2.1 has only been crystallized once. The product cake waswashed with water (99.0 g). The wet product was dried at roomtemperature/ambient pressure for 5 days to yield the title Compound 3(97% yield), recrystallized. After recrystallization according to thisExample 8, Compound 3, that in the pre-crystallization stage had apurity of 99.86%, had purity equal to or about 99.90%. Purity changesupon recrystallization of Compound 3 are shown in Table 7.

TABLE 7 Average Average impurities (%) impurities (%) Relative inCompound in Compound m/z retention 3 before re- 3 after re- Impurity[M + H]⁺ time (RRT) crystallization crystallization I1 278 0.32 n.d.n.d. A2 276 0.48 n.d. n.d. I3 277 0.73 n.d. n.d. A4 395 0.81 n.d. n.d.I5 653 0.86 0.02 n.d. A6 unk 0.87 n.d. n.d. A7 274/733 0.89 n.d. n.d.A8a & A8b 653/unk 0.91 n.d. n.d. I8 505 0.93 n.d. n.d. A10 unk 0.95 n.d.n.d. A11 unk 0.97 n.d. n.d. A12 unk 0.98 n.d. n.d. Compound 3 393 1.0099.86 99.90 A13 unk 1.03 n.d. n.d. I7 407 1.04 0.06 0.05 A15 unk 1.048n.d. n.d. A16 unk 1.057 n.d. n.d. A17 unk 1.064 n.d. n.d. A18a & 512/4091.07 n.d. 0.02 A18b A19 unk 1.08 n.d. n.d. A20 unk 1.10 n.d. n.d. A21unk 1.14 0.04 0.04 A22 847 1.17 n.d. n.d. Abbreviations used in theimmediately preceding Table: nd = not detected, unk = unknown, na = notanalyzed

Example 9 Preparation of5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)-propyl]-2-pyrimidinaminefumarate methanolate (1:2:1), Compound 4

To a 500 mL Erlenmeyer flask which contained 10.012 g (0.0255 mol) of5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)propyl]-2-pyrimidinamine),compound 2, was added 6.2155 g of fumaric acid (2.1 equivalents) and astir bar. To that solid mixture, about 300 mL of 1:1 (weight ratio) hotMeOH:EtOAc were added while heating and stirring. The term “hot solvent”is used here so that such solvent is warm based on such solvent boilingpoint. In some embodiments, hot MeOH:EtOAc was used at a temperature ofabout 50° C. to 60° C. Additional solvent can be added until all thesolids are completely dissolved. The solution mixture was allowed toheat at boiling temperature for another 10 min to give a yellowhomogenous solution. The reaction mixture was removed from the heatingplate and allowed to cool down to room temperature (rt) on the benchtop. Precipitate formed as clusters in the bottom of the flask after 2days. 13.0702 g of5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)-propyl]-2-pyrimidinaminefumarate methanolate (1:2:1), compound 4, as a light yellow solidcrystalline were collected by vacuum filter. XRD profiles confirmed theunique pattern of the desired fumarate salt and according to IR-off gasanalysis, this material is a methanol solvate of the fumarate salt (4.1%weight loss). Table 8 and FIG. 5 display the impurity profiles forcompounds 2 and 4.

In contrast with the observations made in Examples 5 and 7, embodimentsof Compound 4 obtained as described in this Example 9 had impurityprofiles that do not present an overall improvement with respect to thatof Compound 2. In addition, assays of embodiments of this fumarate saltindicated varying compositions including mixtures of mono- anddi-fumarate. Furthermore, fumaric acid presents comparably lowersolubility in solvents that are typically preferable for salt formation.

TABLE 8 Impurity Profile of Compounds 2 and 4 (Example 9) Compound 2Compound 4 Impurity 1 (I1) 0.03 0 Impurity 2 (I2) 0 0.03 Impurity 3 (I3)0.04 0 Impurity 4 (I4) 0.18 0.22 Impurity 5 (I5) 0.37 0.18 Impurity 6(I6) 0.07 0.02 Impurity 7 (I7) 0.17 0.16 Impurity 8 (I8) 0.15 0.07Impurity 9 (I9) 0.08 0 Impurity 10 (I10) 0.09 0.16

Example 10 Preparation of5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)-propyl]-2-pyrimidinaminephosphate (1:1), Compound 5

To a 50 mL Erlenmeyer flask which contained 500.32 mg (1.275 mmol) of5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)propyl]-2-pyrimidinamine),Compound 2 and a stir bar, was added about 20 mL of hot 50:50 MeOH:EtOHsolvent. In some embodiments, hot MeOH:EtOH was used at a temperature ofabout 50° C. to 60° C. A clear yellow solution was obtained. Thesolution was brought to boiling temperature on a hot plate withstirring, and 96 μL of phosphoric acid (85% in water, 1.1 equivalent)was added dropwise. The reaction mixture became cloudy as the acid wasadded but quickly changed to a clear yellow solution as it was stirred.The reaction mixture was left to heat on the hot plate at lowtemperature for another 10 min before being removed and allowed to cooldown to rt on the bench top. The flask was left at room temperatureovernight to allow crystals to precipitate. For this experiment, smallspatula of the phosphate salt was added to the reaction mixture asseeded and left open at rt overnight to form crystals. Very finecrystalline needles are formed in the bottom of the flask after 2 days.531.3 mg (85% yield) of the off white, light yellow solid crystalline5-(4,6-dimethyl-1H-benzimidazol-2-yl)-4-methyl-N-[3-(1-methyl-4-piperidinyl)-propyl]-2-pyrimidinaminephosphate (1:1), compound 5 were collected by vacuum filter.Precipitation will occur at rt after 2 days or more without seeding, butit forms an oil layer in the bottom of the flask if left at coldtemperature (5° C.). Significant losses in the mother liquor wereobserved in some embodiments. Furthermore, this phosphate salt tended toform a sticky oil on the reactor walls, which makes it more difficult tohandle than any of Compounds 2.1 and 3. XRD profiles confirmed thepattern of the desired phosphate salt. As to purity, this phosphate saltdid not show improved impurity segregation ability with respect to thatof Compound 2.1.

Examples 2-5 and 7 describe synthetic methodologies according to thisinvention for compounds such as the following compounds:

In addition to the impurity segregation features of various of suchcompounds as noted in preceding Examples, it is also noted thatpharmaceutically acceptable salts of Compound 2 are generally preferablefor pharmaceutical use to formulations of the free base Compound 2itself. Furthermore, Compound 3 presents itself as a well characterizedform which is generally preferable to anhydrous salts, such as Compounds2.1 and 2.2, that present themselves in more than one form (such aspolymorphs A and B, respectively). When Compound 3 was made either fromthe free base Compound 2 (Example 5) or from the anhydrous hemi-tartrateCompound 2.1 (Example 7), Compound 3 was found to be highly pure atabout 99.86% purity. An additional recrystallization improved its purityto about 99.90%, and no other salt forms where found upon suchrecrystallization. Because no conversion of Compound 3 to other formswas detected, this compound provides the advantageous possibility ofperforming with it aqueous-based formulation development, such as wetgranulation work. Whereas a re-crystallization of Compound 2.1 isdescribed herein, see Example 3, step E, the impurity segregationproperties of Compound 3 are such that its synthesis in the high degreesof purity exemplified herein does not have to rely on are-crystallization of such Compound 2.1, which is presented in theforegoing examples for illustrative purposes.

Example 11 Some Impurity Structural Formulae and Characterizations

TABLE 9 Impurity Designation Characterization I1 Molecular weight 277,Compound of structure I1 I2 Molecular weight 394. I3 Molecular weight276, Compound of structure I3 I4 Molecular weight 652. I5 Molecularweight 652, Compound of structure I5 I6 Molecular weight 732. I7Molecular weight 406, Compound of structure I7 I8 Molecular weight 504,Compound of structure I8 I9 Relative retention time is 1.07. I10Relative retention time is 1.37. I11 Molecular weight estimate is 277

When the material being referred to herein is characterized by sayingthat any given impurity content is “0”, or that such given impurity isnot detected, typically abbreviated as “n.d.” or “nd”, then suchmaterial is also referred to as being “substantially free from” any suchgiven impurity.

Impurities were analyzed according to standard high performance liquidchromatography (HPLC) with detection by mass spectrometry (MS) orultra-violet spectroscopy (UV), finding one or more of the impurity'smass, relative retention time, and amount (as relative area percentage),and they are provided herein by using notation that is typical in suchstandard methodologies. For an illustrative review of the same, see forexample, S. Levin, “High Performance Liquid Chromatography (HPLC) in thepharmaceutical analysis”, Medtechnia (February 2010), which isincorporated herein by reference (describing HPLC modes, HPLC theory,the role of HPLC in drug analysis, and specialized HPLC separations;available at, for example,http://www.forumsci.co.il/HPLC/WEBPharm_Review/HPLC_pharma_Modes-RP.html).

Impurity amounts as reported herein were determined at a level below thelevel allowed in this industry standards. For example, in a validationof the impurity analysis method of Compound 2, a relative standarddeviation of not more than 4% was found (i.e., if the impurity amount yin this case were 0.05%, a relative standard deviation of not more than4% would mean y to be 0.05±0.002%).

While the invention has been illustrated by reference to examples, it isunderstood that the invention is intended not to be limited to theforegoing detailed description.

What is claimed is:
 1. A method of obtaining a purified pharmaceuticallyacceptable salt of a[5-(4,6-dimethyl-1H-benzoimidazol-2-yl)-4-methyl-pyrimidin-2-yl]-[3-(1-methyl-piperidin-4-yl)-propyl]-amine,comprising: forming a hemitartrate salt of the compound of formula (2):

in water to yield an aqueous hemitartrate salt solution; seeding saidaqueous solution with crystal seeds of the tetrahydrate of saidhemitartrate to obtain a seeded aqueous solution; and crystallizing outof said seeded aqueous solution the solid tetrahydrate hemitartrate offormula (3):


2. A method according to claim 1, wherein said solid tetrahydratehemitartrate of formula (3) is substantially free from at leastimpurities I1 and I3 of formulae:


3. A method according to claim 1, wherein said forming a hemitartratesalt comprises reacting compound of formula (2) with L-(+)-tartaric acidin water, and said crystallizing comprises cooling said seeded aqueoussolution to about 5° C.